Halogenated organic compounds



United States Patent HALOGENATED ORGANIC COMPOUNDS Sidney B. Richter,Chicago, 111., assignor to Velsicol Chemical Corporation, Chicago, 111.,a corporation of Illinois No Drawing. Application March 20, 1957 SerialNo. 647,197

8 Claims. (Cl. 71-2.5)

This invention relates to new organic sulfite ethers which aredistinguished by remarkably great herbicidal activity. These newcompounds contain the radical which is characteristic of sulfites, andfurther they contain a wide variety of substituted alkyl groups attachedto the two oxygen atoms in the sulfite group. The substituted alkylgroups themselves can each contain from 2 to 4 carbon atoms. One of saidalkyl groups is halogenated, while the other is attached via an etherlinkage to a 5- or 6-membered cyclic aliphatic radical, which itself canbe halogenated or oxygenated.

In particular, this invention relates to organic sulfites having thegeneral formula wherein R is a cyclic aliphatic radical containing from5 to 6 carbon atoms, y and z are integers from 2 to 4, and X is selectedfrom the group consisting of chlorine, bromine, and fluorine. It hasbeen found that compounds of this invention in which R is a halogenatedor oxygenated cyclic aliphatic radical are very useful substances forthe regulation of plant growth, and products in which R is acyclopentenyl radical are particularly active.

The organic sulfites of this invention are prepared readily and inexcellent yields by the stepwise reaction of thionyl chloride with theappropriate alcohols. The synthesis may be presented schematically bythe following reactions, wherein R y, z, and X are as described above:

may be used to effect these reactions. A preferred range of reactiontemperatures is between 15 and 60, although temperatures below and abovethis range can also be used, since the exact temperature is notcritical. However, the reactions can be quite slow at temperatures below15 C. In certain cases, decomposition of some of the reactants may occurat temperatures above 60 C.

'The compounds of this invention are unexpectedly Patented Aug. 25, 1959very active herbicidal substances even though they do not exhibit anysignificant toxicity toward insects and mites. For example, in tomatowatering tests conducted to study root absorption and translocation,Z-chloroethyl-2-(2-cyelopentenyloxy)ethyl sulfite was formulated into a10% wettable powder and dispersed in water to a concentration of 4,000p.p.m. of actual compound. Ten milliliters of an aliquot part of thisdispersion were applied to the soil surface of young potted tomatoplants (Bonny Best variety) approximately 5 to 7 inches tall. In orderto avoid undue concentration or accumulation of the chemical in anygiven area, 5 holes of diameter about one centimeter and about one inchdeep were punched in the soil surface around the shoot, and the 10 ml.application was divided equally among the 5 holes. Three plants wereused for each application. The treated plants were held under idealgreenhouse conditions for 10 days, provided with subterranean watering,and observed for response to treatment.

After 12 days, it was found that the plants in the pots treated with thesuspension of 2-chloroethyl-2-(2-cyclopentenyloxy)ethyl sulfite werecompletely wilted, and their root structure was disintegrated. On theother hand, growth and root structure in plants not treated with thiscompound were completely normal. In similar soil watering experimentscarried out at a later date, 2-chloroethyl-2-(2-cyclopentenyloxy)ethylsulfite used at a concentration of 4,000 p.p.m. gave tomato plants whichhad root structures which were ,4 of normal after 10 days compared to anuntreated control. The suspension of2-chloroethyl-2-(2-cyclopentenyloxy)ethyl sulfite was also caustic tothe stems of the tomato plants at the soil line.

Experiments were also carried out in which suspensions of these activecompounds were applied directly to the foliage of Bonny Best varietytomato plants. Thus, 2-(2- cyclopentenyloxy)ethyl sulfite was formulatedinto a 10% wettable powder, dispersed in water to a concentration of4,000 p.p.m. and applied to the foliage of fourweek-old potted tomatoplants by dipping the plants therein. Three replicates were used foreach treatment. The treated plants were held under greenhouse conditionsfor 12 days, provided with subterranean watering, and observed forresponse to treatment. After 12 days,

all the plants treated with the suspension of2-chloroethyl-2-(2-cyclopentenyloxy)ethyl sulfite were wilted, and theirroot structures were disintegrated. The growth and root structure ofuntreated control plants were completely normal.

For practical use, the compounds of this invention are formulated andapplied in the manner well known in the art of controlling noxious plantgrowth. For example, these compounds can be formulated into dusts bycombining them with such inert substances as talc or clays, and in thisform they are applied directly to the plants which it is desired todestroy. The compounds can also be dissolved in organic solvents such askerosene or the methylated naphthalenes; or they can be emulsified orsuspended in Water by the addition of emulsifiers or Wetting agents. Theliquid formulations of these active herbicidal compounds are eitherapplied directly to the plants to be controlled by spraying, or the soilin which the plants are growing can be treated directly. Othersubstances such as activators, synergists, spreaders, and adhesives canbe added to the formulations if required. The following examplesillustrate the manner in which the herbicidally useful compounds of thisinvention may be prepared.

Example I 2-(2-cyclopentenyloxy) ethanol, which is the ether-alcoholrequired as an intermediate in the preparation of 2- achloroethyl-Z-(Z-cyclopentenyloxy)ethyl sulfite, was prepared asfollows: 3-chlorocyclopentene (107 g., 1.04 mol.) was added dropwisewith stirring over a period of 1 hour to 200 .ml. of ethylene glycol inthe presence of methyl red indicator. Arnmonia ('18 g., 1.06 mol.) in150 .ml. ethylene glycol was added simultaneously with the,3-chlorocyclopentene at such a rate that the reaction mixture becamebasic to the methyl red only momentarily every 2 to 3 minutes. Thetemperature of the reaction mixture was maintained at 25 to 30. When theaddition was complete, the reaction mixture was allowed to standovernight and was then extracted repeatedly with ethyl acetate. Thesolvent was distilled oil, and the residue was dissolved in ethyl ether,washed with Water, dried over sodium sulfate, and freed of ether bydistillation. The water washings were extracted with ether, and theether solution was Washed with 10% sodium chloride solution, dried oversodium sulfate, filtered, and freed of ether. The combined residues fromthe ether evaporations were distilled in vacuo to give 77 g. (60% oftheory) of 2-(2-cyclopentenyloxy)-ethanol, boiling at 85 to 91 under10mm. pressure and having an index of refraction (D line) of 1.4730 at20 C.

Example II In order to prepare the intermediate 2-chloroethyl Vchlorosulfinate, thionyl chloride (70 g.) was added over a period ofabout 6 hours to 40 g. of ethylene chlorohydrin in a 250 ml.round-bottomed flask protected with a calcium chloride drying tube. Theaddition was made at such a rate that the temperature did not rise above35 during the addition process. The product was distilled to give 76 g.of Z-chloroethyl chlorosulfinate boiling at 84 to 86 under 25 mm.pressure. 7

This intermediate sulfinate was then condensed with2-(2-cyclopentenyloxy)ethanol, prepared as described in Example I, togive the desired 2-chloroethyl-2-(2-cyclopentenyloxy)ethyl sulfite. Thus2-(2-cyclopentenyloxy)- ethanol ('32 g., 0.25 mol.), 300 ml. benzene,and 20 g. pyridine (0.25 mol.) were placed in a 500 ml. roundbottomedflask fitted with a stirrer, thermometer, reflux condenser, and droppingfunnel. The Z-chloroethyl chlorosulfinate (41 g.,-0.25 mol.) prepared asdescribed above was added to the stirred mixture in the flask over aperiod of 75 minutes at a rate such that the temperature did not exceed35. After the addition, stirring was continued for an additional hour.The solution was then filtered, Washed with Water, and dried over sodiumsulfate. The solvent was removed at reduced pressure, and the resultingresidue was fractionated through a 10-inch Vigreux column to give 44 g.(70% of theory) of 2- chloroethyl-Z-(2-cyclopentenyloxy)ethyl sulfite,boiling at 106 to 112 under 0.1 mm. pressure and having an index ofrefraction (D line) of 1.4870 at 24.

Analysis.-C H C1O S: Found: C, 42.05%; H, 5.48%; Cl, 14.15%. Calculated:C, 42.46%; H, 5.89%; Cl, 13.93%.

Example III In order to prepare the intermediate2-(2,3-epoxycyclopentanoxy)ethanol, ethylene glycol (200 cc.) is treatedwith 1-cl1loro-2,3-epoxycyclopentane (.127 g., 1.04 mol.) and ammonia(18 g., 1.06 mol.) in 200 cc. ethylene glycol over a period of 1 hour at2530 in the manner which has been described in Example I. Extraction anddistillationof the reaction-mixture give 2-(2,3- epoxycyclopentanoxy)ethanol.

Example I V 2-chloroethyl-2 (2,3 -epoxycyclopentanoxy ethyl sulfite isprepared as follows: 2-chloroethyl chlorosulfinate (41 g., 0.25 mol.),prepared as described in Example II, is added with stirring over aperiodof 1 hour to a mixture of 2-(2,3-epoxycyclopentanoxy)ethanol (36 g.,0.25 mol.), 300 nil. benzene, and 20 g. pyridine (0.25 101.).

The temperature is kept below 35 during the addition, after which thereaction mixture is stirred for an addi tional hour. The product isworked up and distilled in the manner described in Example II to givethe desired 2-chloroethyl-2-(2,3-epoxycyelopentanoxy)ethyl sulfite.

Example V distilled in vacuo to give 3-(2-chlorocyclopentanoxy)--propanol.

Example VI In order to prepare the intermediate 2-bromoethylchlorosulfinate, ethylene bromohydrin (62 g.) is treated with thionylchloride (70 g.) in a manner similar to that described in Example II.Distillation gives the desired 2-bromoethyl chlorosulfinate.

2-brornoethyl-3-(2-chlorocyclopentanoxy)propyl sulfite is then preparedas follows: The 2-bromoethyl chlorosulfinate (52 g., 0.25 mol.) obtainedabove is added dropwise over a period of one hour to a stirred mixtureof 2-(2-chlorocyclopentanoxy)propanol (44 g., 0.25 mol.), prepared asdescribed in Example V, and 20g. pyridine (0.25 mol.) in 400 cc. xylene.The temperature is maintained at 30 or below during the addition, afterwhich the reaction mixture is allowed to stand for several hours. Thereaction product is filtered, washed with water, dried over sodiumsulfate, and distilled in vacuo. After the removal of the solvent and asmall forerun, the fraction consisting of2-brornoethyl-3-(2-chlorocyclopentanoxy)propyl sulfite is collected.

Example VII The following spray formulation of the product from ExampleII is prepared by mixing the ingredients intimately in the givenpercentage proportions by weight:

Percent 2-chloroeth'yl-2(2-cyclopentenyloxy)ethyl sulfite 33 AntaroxA-400 44 Methanol 23 Antarox A-400 is the trade name under which anonionic detergent of the aromatic polyethylene glycol ether type issold. The above concentrate is diluted with water for use.

Example VIII The product from Example IV is formulated as follows, wherethe ingredients are mixed thoroughly in the given Triton X- is the tradename under which an emulsifier of the alkyl aryl polyether alcohol typeis sold. The above "concentrate is diluted as is desired for use.

Example IX A formulation as follows is prepared from the product ofExample VI. The ingredients are combined in the given percentageproportions by weight.

Percent 2-bromoethyl-3-(2-chlorocyclopentanoxy)propyl sulfite AntaroxA-400 5 Velsicol AR-SO 51 Antarox A-400 is the trade name under which anonionic detergent of the aromatic polyethylene glycol ether type issold. Velsicol AR-50 is a methylated naphthalene solvent. Theconcentrate is diluted for use.

It is obvious that a wide variety of other chemical compounds can besubstituted for the specific compounds used as starting materials in theabove examples to give other herbicidal compositions which fall withinthe scope of this invention. Thus products in which R is a sixmemberedring can be obtained by using such compounds as 3-chlorocyclohexene ormonochlorocyclohexane instead of the 3-chlorocyclopentene in Example I,whereupon the final herbicidal products from Example II will be2-chloroethyl-2-(2-cyclohexenyloxy)ethyl sulfite and2-chloroethyl-2-(cyclohexyloxy)ethyl sulfite, respectively. Productswith halogenated or oxygenated six-membered rings can be prepared byusing, for example, 1,2-dichlorocyclohexane or1-chloro-2,3-epoxycyclohexane. The final herbicidal products will thenbe 2-chloroethyl-2-(2-chlorocyclohexyloxy)ethyl sulfite and2-chloroethyl-2-(2,3- epoxycyclohexyloxy)ethyl sulfite, respectively.The group (CH can be made to contain 4 carbon atoms, for example, byusing 1,4-butaneodiol in place of ethylene glycol in Example I,whereupon the final herbicidal product from Example II will be2-chloroethyl-2-(2-cyclopentenyloxy)butyl sulfite. Similarly, (CH can bemade to contain 3 or 4 carbon atoms by using 3-chloro-lpropanol or4-chloro-l-butanol, respectively, in place of the ethylene chlorohydrinin Example II, with the result that the final products will be3-chloropropyl-2-(2-cyclopentenyloxy)ethyl sulfite and4-chlorobutyl-2-(2-cyclopentenyloxy)ethyl sulfite, respectively.Further, X can readily be fluorine instead of chlorine or bromine, sincecompounds such as 2-fluoroethanol can be used in place of ethylenechlorohydrin as described in Example I, whereupon the final herbicidalproduct from Example II will be2-fluoroethyl-2-(Z-cyclopentenyloxy)ethyl sulfite.

I claim:

1. A composition of matter having the structure oR,-o--(0H,),-0-ii-o-(oH,).X wherein R is a chlorinated alicyclicsaturated hydrocarbon radical containing from 5 to 6 carbon atoms in thering and wherein said chlorine is attached directly to said ring, y andz are integers from 2 to 4, and X is selected from the group consistingof chlorine, bromine, and fluorine.

2. A composition of matter having the structure R O-(GHg),-O-iil0(CH1),Xwherein R is an alicyclic saturated hydrocarbon radical having an epoxygroup in the 2,3-position and containing from 5 to 6 carbon atoms in thering, y and z are integers from 2 to 4, and X is selected from the groupconsisting of chlorine, bromine, and fluorine.

3. 2-chloroethyl-2-(Z-cyclopentenyloxy)ethyl sulfite.

4. 2-ch1oroethyl-2-(2,3-epoxycyclopentanoxy)ethyl sulfite.

5. 2 bromoethyl 3 (2 chlorocyclopentanoxy)propyl sulfite.

6. A herbicidal composition comprising an inert carrier and a herbicidaltoxic amount of the composition of matter described in claim 8.

7. A method of destroying undesirable plants which comprises contactingsaid plants with a herbicidal composition comprising an inert carrierand as the essential active ingredient, in a quantity which is injuriousto said plants, a composition of matter as described in claim 8.

8. A composition of matter having the structure wherein R is selectedfrom the group consisting of alicyclic hydrocarbon radical; having from5 to 6 carbon atoms in the ring, alicyclic saturated hydrocarbonradicals having an epoxy group in the 2,3-position and from 5 to 6carbon atoms in the ring, and chlorinated alicyclic saturatedhydrocarbon radicals having from 5 to 6 carbon atoms in the ring andwherein said chlorine is attached directly to said ring, y and z areintegers :from 2 to 4, and X is selected from the group consisting ofchlorine, bromine, and fluorine.

References Cited in the file of this patent UNITED STATES PATENTS2,529,493 Harris et al. Nov. 14, 1950 2,529,494 Harris et al. Nov. 14,1950 2,644,008 Glenn et a1 June 30, 1953 2,802,727 Harris et a1. Aug.13, 1957

6. A HERBICIDAL COMPOSITION COMPRISING AN INERT CARRIER AND A HERBICIDALTOXIC AMOUNT OF THE COMPOSITION OF MATTER DESCRIBED IN CLAIM
 8. 8. ACOMPOSITION OF MATTER HAVING THE STRUCTURE